SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567816b13a34a7f2f487cf2a96e1f5dd8b86fbbe6bafc5661f6a8dcc476c5eff' 
  AND token = '9hgV3+I7hmeBQqPreIjKHJ87jWS+s8cOnROvKbqUxHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}